Process of case-hardening metals and alloys.



- Metals and Alloys, of which the following is UNITED sra'rns PATENTonnnnaz:

MAXIMILIAN GRAB AND OTTO PESCHEL, 'JF TEZEL, NEAR BERLIN, GERMANY.

PROCESS OF CASE-HARDENING METAILS AND ALLOYS,

No Drawing.

To all whom it may concern: I

Be it known that we, MAXIMILIAN GRKF and OTTO PESCHEL, subjects of theGerman Empire, residing at Tezel, near Berlin, Germany, have inventednew and useful Improvements in Processes of Case-Hardening aspecification.

The process forming the subject of the present invention has for itsobject the uniform and speedy incorporation of carbon in articles beingcase hardened. Itis based on the recognition of the fact that theincorporation of carbon from the carbonaceous material during theincandescing process must be more efliciently accomplished, the morethoroughly and uniformly the articles; are incased bythe carbonaceouscase hardening material, which is as homogeneous as possible, the morecompletely and 'more rapidly the heat is developed in the casing, andthe more directly the carbonization of the articles by the casehardening'materiaL By the new process the use of expensive casehardening materials and'mixtures is-- avoided since the said new processcontent" plates exclusively the use of small wood in fibered form suchas shavings, sawdust,

wood-wool or the like or other wastema r Specification of LettersPatent. Application filed October 17,

Patented Feb. 20, 1912.

1910. Serial No. 587,617.

terial, the whole or 3. part of which ma if desired be impregnatedbefore use wita suitable liquid ignifuge so as more or less to 3(Examplesof such. ignifuges are a solution of borax and 35.

retard the combustion process.

magnesium sulfate, a solution of sodium silicate or a solution ofpotassium silicate.)

To the wood after it isdried are added small quantities of soda andcolophony solely for keeping clean the surface of the metal to be casehardened, the carbonaceousmaterial amounting to 90 9570 of the whole.

Having described ourinvention whatwe desire to secure y Letters Patent.of the XUni'ted States is:'-'-. L .The process of case'li'ardeningmetals cons'isting' in incasing the metal in small wood infibered form impr ated with an ignifu'ge' together with a ditions of'soda and colophony and bringing the metal to incandescenc'e. i I Intestimony whereof we have signed our names to this specification in thepresence of two subscribing witnesses.

'MAXIMILIAN GRAFI .7 OTTOPESCHEL.

Witnesses HENRY HASPEB,

- WOLDEMAR Haur'r.

